The Cawthron Institute has worked alongside regional councils to verify the processes and methods used for data collection, laboratory analysis of samples collected and the statistical analysis and interpretation of the results presented.

If all Cawthron ticks are green, then you can trust this data. However, if one or more ticks are orange, then conclusions should be treated with some caution.

All samples were collected using approved field protocols and have been analysed in accredited laboratories. Therefore the data shown here has been collected and analysed following best practice.

State

All samples were collected using approved field protocols and have been analysed in accredited laboratories.

Trend - SAMPLING FREQUENCY

Samples are collected bimonthly at this site. Proposed national guidelines suggest monthly sampling is required for trend analysis. Therefore, any trends shown here are less robust than those calculated from data collected monthly. New Zealand's councils are currently reviewing their sampling procedures and aim to adjust their sampling frequency to monthly. This will increase the robustness of the trend analyses.

Bacteria

E. coli

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State

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State

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NOF Band

N/A

NOF Band

Trend

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Sample history at this site

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E. coli samples for Hikuwai at No4 Br

n/100ml

What is this graph showing me?

This graph is displaying E. coli concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

What do the icons mean?

For at least half the time, the estimated risk is <1 in 1000 (0.1% risk). The predicted average infection risk is 1%*.

B

For at least half the time, the estimated risk is <1 in 1000 (0.1% risk). The predicted average infection risk is 2%*.

C

For at least half the time, the estimated risk is <1 in 1000 (0.1% risk). The predicted average infection risk is 3%*.

D

20-30% of the time, the estimated risk is >=50 in 1000 (>5% risk). The predicted average infection risk is >3%*.

E

For more than 30% of the time, the estimated risk is >=50 in 1000 (>5% risk). The predicted average infection risk is >7%*.

* The predicted average infection risk is the overall average infection to swimmers based on a random exposure on a random day,
ignoring any possibility of not swimming during high flows or when a surveillance advisory is in place (assuming that the
E. coli
concentration follows a lognormal distribution). Actual risk will generally be less if a person does not swim during high flows.

Clarity

State

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Trend

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Sample history at this site

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Black Disc samples for Hikuwai at No4 Br

metres

What is this graph showing me?

This graph is displaying Black Disc readings over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

State

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Trend

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Sample history at this site

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Turbidity samples for Hikuwai at No4 Br

NTU

What is this graph showing me?

This graph is displaying Turbidity levels over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

Nitrogen

State

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Trend

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Sample history at this site

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Total Nitrogen samples for Hikuwai at No4 Br

g/m3

What is this graph showing me?

This graph is displaying Total Nitrogen concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

State

State

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NOF Band

N/A

NOF Band

Trend

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Sample history at this site

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Total Oxidised Nitrogen samples for Hikuwai at No4 Br

g/m3

What is this graph showing me?

This graph is displaying Total Oxidised Nitrogen concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

Water quality is not considered suitable for the designated use.Impacts on growth of multiple species, and effects starts approaching acute impact level (i.e. risk of death) for sensitive species at higher concentrations (>20 mg/L).

State

State

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NOF Band

N/A

NOF Band

Trend

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Sample history at this site

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Ammoniacal Nitrogen samples for Hikuwai at No4 Br

g/m3

What is this graph showing me?

This graph is displaying Ammoniacal Nitrogen concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

Phosphorus

State

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Trend

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Sample history at this site

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Dissolved Reactive Phosphorus samples for Hikuwai at No4 Br

g/m3

What is this graph showing me?

This graph is displaying Dissolved Reactive Phosphorus concentrations over the selected time period. You can adjust this period by changing the dropdowns. These records form the basis for the state and trend indicators displayed on the dashboard. This data is raw and has not had any methodology applied to it.

Taxonomic richness is the number of different taxa present in an ecological community identified to the best possible level.

Taxa richness history at this site

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Taxa richness for Hikuwai at No4 Br

Number of taxa

Percent EPT richness

The median of the last 5 years of data

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EPT are macroinvertebrates that are sensitive to water pollution. These are Ephemeroptera (mayfly), Plecoptera (stonefly) and Trichoptera (caddisfly).

EPT history at this site

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Percent EPT richness for Hikuwai at No4 Br

EPT %

Can I trust this data?

The Cawthron Institute has worked alongside regional councils to verify the processes and methods used for macroinvertebrate data collection, processing of the data in the laboratory, quality control in the field and laboratory and the statistical analysis and interpretation of the results presented.

Macroinvertebrates are sampled at this site as part of council's stream health monitoring programme, as recommended by proposed national guidelines.

Sampling - Frequency

Macroinvertebrate sampling is done annually or more frequently at this site as recommended by proposed national guidelines. Therefore, data shown here follow current best practice guidelines.

Sampling - Protocols

This site is a hard-bottomed site and appropriate sampling protocols have been applied. Data shown here have been collected using current best-practice.

Sampling - Habitat

Macroinvertebrate sampling is done in riffle habitat at this site. Data shown here are therefore following best practice.

Sampling - Stand-down period

This council does not collect any macroinvertebrate samples for up to two weeks after a flood greater than three times the median flow as recommended by proposed national guidelines. Therefore, data collected at this site is following best practice.

Processing - Protocol

Samples at this site have been processed following protocol P2 which is recommended by proposed national guidelines. However, the individual count number has been reduced from 200 to 100 (with a scan for rare taxa). Data processed at this site are therefore not following best practice and conclusions based on this data need to be treated with caution.

Quality Control - Field

Field data collected at this site had no quality control applied to it.

Quality Control - Lab

Data processed at this site has had one of the three Laboratory Quality Control Protocols (i.e., QC1, QC2,Q C3) applied. Data shown here is more robust than data with no laboratory QC applied.